
(d) Safetygym-PG
<FIGURE>
  
Refer to [1]}. The observation space (\(\mathcal {S} \in \mathbb {R}^60\) ) contains ego information and Lidar information (towards hazards and the goal respectively), etc. The action space (\(\mathcal {A} \in \mathbb {R}^2\) ) denotes the linear velocity and angular velocity of the point mass. The point mass is rewarded for getting close to the green destination. However, it is the agent receives \(+1\)  cost signal if it overlaps with the virtual blue hazards. Due to the original point-goal environment is not designed for zero-cost tasks, we inherit the setting as [2]}, where the number of hazards is 8 and the radius of them is 0.3m.

